1. Field of the Invention
The present invention relates to a thermal activation apparatus for a heat-sensitive adhesive sheet, which heats and thermally activates a heat-sensitive adhesive layer formed on one surface of a sheet-like base material.
2. Description of the Prior Art
In recent years, a heat-sensitive adhesive sheet has been used as a sheet put on a product. The heat-sensitive adhesive sheet is a printing medium in which a sheet base material has a heat-sensitive adhesive layer having no adherence in ordinary circumstances but exhibiting its adherence under heating on one surface, and has a printable layer on the other surface. For example, the sheet has been widely used as a POS sheet for food products, distribution sheets, delivery sheets, medical sheets, baggage tags, and labels on bottles and cans.
Proposed as a printer for a heat-sensitive adhesive sheet for effecting printing on such heat-sensitive adhesive sheets is a printer having a thermal activation mechanism where a heat-sensitive adhesive layer of a heat-sensitive adhesive label is heated in contact with a head having plural resistor elements (heater elements) provided on a ceramic substrate as a heat source like a thermal head used for a printing head for a thermal printer (see Patent Document JP 11-079152 A for example).
Referring now to FIG. 4, a general structure for a conventional printer for a heat-sensitive adhesive sheet is described. The printer for a heat-sensitive adhesive sheet of FIG. 4 is composed of a roll containing unit B for holding a rolled, tape-like heat-sensitive adhesive sheet (heat-sensitive adhesive label A), a printing unit C for effecting printing on the heat-sensitive adhesive label A, a cutter unit D for cutting the heat-sensitive adhesive sheet A into a label with a predetermined length, and a thermal activation unit E as a thermal activation apparatus for thermally activating a heat-sensitive adhesive layer of the heat-sensitive adhesive label A.
The printing unit C is constructed of a printing thermal head G having plural heater elements F composed of plural, relatively small resistor elements arranged in a width direction so as to enable dot printing, a printing platen roller H brought into pressure contact with the printing thermal head G (heater elements F), and the like. In FIG. 4, the printing platen roller H is rotated clockwise to transport the heat-sensitive adhesive label A to the right.
The cutter unit D is adapted to cut the heat-sensitive adhesive label A, which has undergone printing with the printing unit C, to an appropriate length and is composed of a movable blade I operated by a drive source (not shown) such as an electric motor with a stationary blade J opposing the movable blade I, and the like.
The thermal activation unit E is constructed of a thermal-activation thermal head L as heating means having a heater element K, a thermal activation platen roller M as transporting means for transporting the heat-sensitive adhesive label A, a drawing roller N for drawing the heat-sensitive adhesive label A fed from the printing unit C side in between the thermal-activation thermal head L (heater element K) and the thermal activation platen roller M, and the like. In FIG. 4, the thermal activation platen roller M is rotated in a direction (counterclockwise direction) opposite to the rotation direction of the printing platen roller H to transport the heat-sensitive adhesive label A in a predetermined direction (to the right).